Copy strip feed error correcting device

ABSTRACT

A device adapted for use with copying apparatus wherein the feed speed of an original and a strip of photosensitive material can be set at any level as desired, comprising a plurality of detector elements disposed in the path of travel of the strip of photosensitive material and the original respectively for detecting their arrival at respective predetermined positions, and a plurality of variable timers each adapted to be rendered operative after a lapse of time varying in inverse proportion to the feed speed. Upon receipt of signals from the detector elements, the timers are rendered operative after the lapse of a preset time and actuate a first electromagnetic means moving the original ahead of the strip of photosensitive material for a predetermined distance and another electromagnetic means for actuating a cutter for cutting the strip of photosensitive material to provide a sheet of a length consistent with the length of the original. The device is effective to preclude any errors which might otherwise be made in the feed of the strip of photosensitive material when the feed speed is varied.

United States Patent 1 [I l 3,893,360 Yano et al. 1 July 8, 1975 COPY STRlP FEED ERROR CORRECTING Primary ExaminerEvon C, Blunk DEVICE [75] Inventors: Takashi Yano; Yoichi Shibuya;

Satoshi Kanda, all of Yokohama; Shin Umeda, Tokyo, all of Japan [73] Assignee: Ricoh Co., Ltd., Tokyo, Japan [22] Filed: May 30, 1973 [2]] Appl No.: 365,215

[30] Foreign Application Priority Data June 14, 1972 Japan 1, 4170341 [52) US. Cl. 83/203; 83/362; 83/363; 271/9; 355/29; 355/97; 270/58 [51] Int. Cl B26d 5/34; B65h 3/44 [58] Field of Search 355/28, 29, 97. 13, 107', 83/203, 205, 354, 362, 363; 271/9; 270/58 (56] References Cited UNITED STATES PATENTS 3,4l4,255 12/1968 Umahashi 271/9 X 3,537,787 11/1970 Murgas et all A. 3,564,960 2/l97l Foulks 355/13 X 3,595,561 7/l97l Leblant 271/9 3,614,306 10/1971 Goldberg .1 83/203 X Assistant Examiner-Robert Saifer Attorney, Agent, or Ft'rmCooper, Dunham, Clark, Griffin & Moran [57] ABSTRACT A device adapted for use with copying apparatus wherein the feed speed of an original and a strip of photosensitive material can be set at any level as desired, comprising a plurality of detector elements disposed in the path of travel of the strip of photosensitive material and the original respectively for detecting their arrival at respective predetermined positions, and a plurality of variable timers each adapted to be rendered operative after a lapse of time varying in inverse proportion to the feed speed. Upon receipt of signals from the detector elements, the timers are rendered operative after the lapse of a preset time and actuate a first electromagnetic means moving the original ahead of the strip of photosensitive material for a predetermined distance and another electromagnetic means for actuating a cutter for cutting the strip of photosensitive material to provide a sheet of a length consistent with the length of the original. The device is effective to preclude any errors which might otherwise be made in the feed of the strip of photosensitive material when the feed speed is varied.

2 Claims, 11 Drawing Figures @MEHTEMUL 8 I915 3.893360 SHEET 1 DISTANCE FEED SPEED DRIVE 52 MEANS PATEMTEML 8 I975 3,893,360 SHEET 2 DIAL ROTATION FEED SPEED TIME LAG DISTANCE FEED SPEED PATENTED UL 191s SHEET FIG.7

FIG.8

FEED SPEED O b C C FEED SPEED COPY STRIP FEED ERROR CORRECTING DEVICE BACKGROUND OF THE INVENTION This invention relates to copy strip feed error correcting devices, and more particularly it is concerned with a device for precluding errors which might otherwise be produced in the feed of a strip of photosensitive material when the feed speed of the strip of photosensitive material and an original is varied.

In one type of copying apparatus, there is provided an automatic strip feed system in which the arrival at a predetermined position of a leading end of a strip of photosensitive material paid out from a roll is detected, and an original which temporarily stops in a predetermined position after being fed to the copying apparatus is moved ahead of the strip of photosensitive material for a predetermined distance at the same rate as the strip of photosensitive material. When a trailing end of the original reaches a predetermined position, the arrival is detected by a sensor and a cutter is actuated to cut the strip into a sheet of a length consistent with the length of the original. In such copying apparatus, there is also provided a speed varying means for varying the feed speed of the original and the strip of photosensitive material as desired.

When the feed speed of the original and the strip of photosensitive material is varied by the speed varying means, there will be produced variations in the distance for which the original moves ahead of the strip of photosensitive material and the length of a photosensitive sheet severed by cutting from the strip of photosensitive material. The variations are such that their values grow larger in proportion to the feed speed of the original and the strip of photosensitive material as shown in FIG, I by characteristic curves A and Bo.

In FIG. 1, the values of variations set forth along the ordinates are plotted against the values of the feed speed of the original and the strip of photosensitive material set forth along the abscissae. The characteristic curve Ao representing the difference in position between the original and the strip of photosensitive material and the characteristic curve Bo representing the length of a photosensitive sheet to be severed from the strip of photosensitive material show that when the feed speed of the original and the strip of photosensitive material is increased there is a growing deviation from the predetermined value of distance for which the original moves ahead of the strip of photosensitive material in spite of such value having to be constant irrespective of the change in the feed speed. Also, the length of a photosensitive sheet to be severed from the strip of photosensitive material becomes increasingly greater when the feed speed is increased than the predetermined length for such sheet which should be consistent with the length of the original in spite ofa variation in the feed speed of the original and the strip of photosensitive material. This phenomenon is due to the fact that a distance or a length varies in relation to time I and velocity v.

More specifically, an electromagnetic means sensing the arrival of the leading end of the strip of photosensitive material at a predetermined position and causing the original to start moving and an electromagnetic means sensing the arrival of the trailing end of the original at a predetermined position and actuating a cutter may be delayed in starting their action due to inertia of their mechanical parts or delay in the rise time of their electric parts, but the time interval ll during which the first mentioned means remains operative including the aforementioned actuation time lag and the time interval 12 during which the last mentioned means remains operative including the aforementioned actuation time lag are constant. Thus the length of a photosensitive sheet severed from the strip can be expressed as the product of the time interval r1 and the feed speed I while the distance for which the original moves ahead of the strip of photosensitive material can be expressed as the product of the time interval 2 and the feed speed V.

Now, if the feed speed v of the original and the strip of photosensitive material is varied by a speed varying means, the product of II and v or the length of the photosensitive sheet will show a change and the product of i2 and v or the distance for which the original moves ahead of the strip of photosensitive material will also show a change. The values of these changes take the form of the characteristic curves shown in FIG. I.

This phenomenon will be described more in detail. The length L of the photosensitive sheet severed from the strip of photosensitive material can be expressed by the formula L=t1 X v where t I is the time interval during which the electromagnetic means for sensing the strip of photosensitive material remains operative and v is the feed speed of the original and the stripof photosensitive material as aforesaid. Thus, if the electromagnetic means is actuated earlier than when it will sense the strip of photosensitive material by an actuation time lag to 31 I, it will be possible to sever a photosensitive sheet of a length consistent with the length of the original as designed. Likewise, the distance D for which the original moves ahead of the strip of photosensitive material can be expressed by the formula D :2 X r. If the electromagnetic means is actuated earlier than when it will sense the original by an actuation time lag [0-2, it will be possible to set at a predetermined level the distance for which the original moves ahead of the strip of photosensitive material.

In this type of copying apparatus, the feed speed of the original and the strip of photosensitive material can be varied as desired. If the feed speed is increased to v Av, the length Lo of the photosensitive sheet severed from the strip can be expressed by the formula L0 :1 .(v Av). Thus the length of the photosensitive sheet severed from the strip will be greater than the predetermined length by rl.Av. Likewise, the distance Do for which the original moves ahead of the strip of photosensitive sheet can be expressed by the formula D0 t2.(v Av). Thus the distance for which the original moves ahead of the strip of photosensitive material will be greater than the predetermined distance by !2.Av.

These errors tLAv and r2.Av will vary in value each time the feed speed of the original and the strip of photosensitive material is varied, since the feed speed can be varied continuously. Thus difficulty is experienced in correcting these errors.

SUMMARY OF THE INVENTION This invention provides a copy strip feed error correcting device, adapted for use with copying apparatus of the type wherein an original and a strip of photosensitive material are fed together, which device is effective to preclude errors which might otherwise be made in the length of a photosensitive sheet to be severed from the strip of photosensitive material and the distance for which the original is designed to move ahead of the strip of photosensitive material when the feed speed of the original and the strip of photosensitive material is varied, by using variable timers each adapted to become operative after the lapse of a time which may vary in inverse proportion to the feed speed of the original and the strip of photosensitive material to actuate an electromagnetic means.

The invention obviates the aforementioned disadvantages of conventional copying apparatus of the type described in which the feed speed of the original and the strip of photosensitive material can be varied as desired by a speed varying means. The device according to the invention comprises variable timers each having an inverse functional characteristic and becoming operative after a lapse of ofa time which may vary in inverse proportion to the feed speed of the original and the strip of photosensitive material, a speed varying means capable of varying the feed speed of the original and the strip of photosensitive material and coupled to such variable timers, and electromagnetic means adapted to be actuated by signals from the variable timers. The device is simple in construction and high in efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing variation characteristics of the length of a photosensitive sheet to be severed from a strip of photosensitive material and the distance for which an original is designed to move ahead of the strip of photosensitive material which are exhibited when the copying speed is varied;

FIG. 2 and FIG. 3 schematically show essential portions of a copying apparatus incorporating the invention;

FIG. 4 to FIG. 6 are diagrams of characteristics curves of the speed varying means and the variable timers shown in FIG. 2 and FIG. 3;

FIG. 7 is a circuit diagram of the variable timer used for the device according to the invention shown in FIG. 2 and FIG. 3;

FIG. 8 and FIG. 9 are diagrams of characteristics curves of the timer shown in FIG. 7;

FIG. 10 shows the speed varying means connected to the variable timer; and

FIG. II is a circuit diagram showing the manner of operation of the variable timer.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION FIG. 2 shows a mechanism using a variable timer 19 for feeding an original and a strip of photosensitive material at the same speed with the original moving ahead of the strip of photosensitive material a predetermined distance even if the feeding speed is varied. An original II to be copied abuts at its leading end against a stop per 12 and temporarily stops when fed to the copying apparatus. At the same time, the original 11 is sensed by a sensing means 50, and a strip of photosensitive material I3 is paid out from a roll 16 by feed rollers 14 and 15 operated by drive means 51 and moved in the direction of an arrow at a speed set by a speed varying means 17. When the leading end of the strip of photosensitive material 13 reaches a predetermined position, a detector element 18 which may be a microswitch I8 has its variable contact pushed by the strip 13, so that the microswitch 18 is turned on. This supplies an actuation signal to the variable timer 19 which is rendered opera tive after lapse of a time at which the timer is set following reception of the actuation signal from the microswitch 18 and supplies a current to a solenoid 20. Ener gization of the solenoid 20 removes the stopper I2 from the path of travel of the original 11 and at the same time actuates a drive means 52 for moving the original. Like the rollers I4 and 15, the drive means moves the original 11 in the direction of an arrow in parallel relation to the strip of photosensitive material I3 at a speed set by the speed varying means 17.

The variable timer I9 comprises a variable element connected to a knob I71 for manipulating the speed varying means 17 and setting a time which lapses after reception of an actuation signal from the detector element I8 before the timer is rendered operative so that the time elapsing before the timer is rendered operative and the feed speed set by the speed varying means I7 may be in inverse proportion to each other. Thus the time elapsing before the variable timer I9 is rendered operative is set according to the feed speed set by the speed varying means 17. This permits the relative positions of the original I1 and the strip of photosensitive material 13 to be maintained as designed even if the feed speed of the original and the strip of photosensitive material is varied by the speed varying means I7.

FIG. 3 shows a mechanism using a variable timer 22 for actuating a cutter 24 when the trailing end of the original I1 reaches a predetermined position so as to sever from the strip 13 a photosensitive sheet of a length consistent with the length of the original 11 even when the feed speed is varied. As shown, a detector element 21 which may be a microswitch detects the arrival of the original at a predetermined position and has its movable contact actuated. This supplies an actuation signal to the variable timer 22 which is rendered opera tive after lapse of a predetermined time and supplies a current to a solenoid 23. Energization of the solenoid 23 results in a movable cutting edge 25 of the cutter 24 rotating and severing a photosensitive sheet from the strip I3.

The variable timer 22 comprises a variable element connected to the knob I71 for manipulating the speed varying means 17 and setting a time which lapses after reception of an actuation signal from the detector element 21 before the timer is rendered operative so that the time elapsing before the timer 22 is rendered opera tive and the feed speed set by the speed varying means 17 may be in inverse proportion to each other. This permits a photosensitive sheet of a length consistent with the length of the original 11 to be severed from the strip I3 at all times even if the feed speed of the original and the strip of photosensitive material is varied. The original 11 is superposed on the photosensitive sheet 13a severed from the strip and fed to an exposing station where the sheet 13a is exposed to an optical image of the original and has its electrostatic latent image formed thereon. The latent image is developed into a visible image in a developing station.

When the speed varying knob 171 is manipulated to set the speed varying means 17 at any feed speed as desired on a dial calibrated in speeds, the set feed speed is in a linear proportional relation to the speed dial as shown in FIG. 4. The time lag inherent in actuating the drive means 52 for moving the original 11 by sensing the leading end of the strip of photosensitive material 13 due to mechanical inertia or an electric rise time characteristic is constant as indicated by a broken line a in FIG. 5. The time elapsing before the variable timer 19 is rendered operative is an inverse function of the feed speed set by the speed varying means 17 as indicated by a dash-and-dot line b in FIG. 5. Accordingly the overall time delay is as indicated by a solid line d in FIG. 5. Thus the original 11 will be disposed relative to the strip of photosensitive material 13 such that the former moves ahead of the latter by a distance which is constant as shown in FIG. 6 irrespective of a change in the feed speed set by the speed varying means 17. This distance can be set at any value as desired by moving the microswitch 18 in a direction parallel to the direction of movement of the strip of photosensitive material 13.

The electromagnetic means sensing the trailing end of the original and producing a signal to instruct the cutter to sever a photosensitive sheet from the strip 13 also has an inherent time lag which is set by The time elapsing before the variable timer 22 is rendered operative is an inverse function of the feed speed set the speed varying means 17. Accordingly the length of a photosensitive sheet severed by the cutter 24 from the strip 13 is constant irrespective of a change in the feed speed set by the speed varying means 17. By moving the microswitch 21 in a direction parallel to the direction of movement of the original 11, it is possible to set the length of the photosensitive sheet severed from the strip 13 at any value as desired.

The variable timers 19 and 22 may be either electronic timers each using a variable resistor or a variable capacitor for setting at any value as desired the time which elapses before they are rendered operative, or mechanical timers. The electronic timers may be of the construction as shown in FIG. 7. In the figure, terminals P and N are connected to a direct current power source through a series circuit comprising the solenoid 20 (23) and microswitch 18 (21). Connected to the terminal P through a resistor R1 is a cathode of a constant-voltage diode ZD whose anode is connected to the terminal N. The cathode of constant-voltage diode ZD is also connected to the terminal N through a series circuit comprising a resistor R2, variable resistor VR and capacitor C l and through a series circuit comprising resistors R3, R4 and R5.

Connected to the junction of the variable resistor VR and capacitor C l is an anode of a programmable unijunction transistor PUT whose cathode is connected to the terminal N through a parallel circuit comprising a resistor R6 and a capacitor C2 and to a gate of a thyristor SCR. A gate of the programmable unijunction transistor PUT is connected to the junction of the resistors R4 and R5 while an anode and a cathode of the thyristor SCR are connected to the terminals P and N respectively. The programmable unijunction transistor PUT is a unijunction transistor which can set the gate voltage at any value as desired by varying external resistance as is well known.

The variable timer 19 (22) constructed as aforementioned operates such that when the microswitch 18 (21) is closed a current is passed to the terminal P through the load 20 (23). The current does not fire the thyristor SCR, so that its value is too small to actuate the load 20 (23). A constant voltage is produced between two terminals of the constant-voltage diode ZD as a voltage is impressed between the terminals P and N. The constant voltage is impressed on a time constant circuit comprising the resistor R2, variable resistor VR and capacitor C 1, so that the capacitor C1 is charged.

The constant voltage produced in the constant-voltage diode ZD is reduced in value by the resistors R3, R4 and R5 to a voltage of a predetermined value which is impressed on the gate of programmable unijunction transistor PUT. When the charge of the capacitor C1 becomes higher than the gate voltage of the transistor PUT, the latter is fired and supplies a pulse to the gate of the thyristor SCR.

When a pulse is supplied to the gate. thyristor SCR is fired and a current of a high value flows to the load 20 (23) to actuate the same. The time during which the timer 19 remains operative is a time that elapses after the current is passed between the terminals P and N before the thyristor SCR is fired. Thus the time during which the timer remains operative can be varied by varying the value of the variable resistor VR. As is well known, variable resistors may each have a resistance varying characteristic A, B, C or the like. The variable resistor VR used in the present invention has a resistance varying characteristic C.

If the value of the resistor R4 is made variable as expressed by the formula Rc, Ra, Rb (Rb Ra Rc then it is possible to vary the time during which the timer 19 (22) is operative relative to the value of the variable resistor VR or the feed speed set by the speed varying means 17 as shown in FIG. 8. Also, if the value of the capacitor C1 is varied as expressed by the formula Ca. Cb (Cb Cu Cc), then it is possible to vary the time during which the timer 19 (22) is operative relative to the value of the variable resistor capacitor or the feed speed set by the speed varying means 17 as seen in FIG.

The variable timer 19 (22) is built in a copying apparatus as shown in FIG. 10, for example. The terminals P and N of the timer 19 (22) are connected between output terminals of the rectifying circuit REC through the microswitch 18 (21), solenoid 20 (23) resistor R7 and diode D connected in series, and an alternating current source AC is connected between input terminals of the rectifying circuit REC. A smoothing capacitor C3 is connected in shunt to the series circuit comprising the variable timer 19 (22), solenoid 20 (23) and microswitch 18 (21).

The variable resistor VR of the timer 19 (22) is supported by a resistance varying rotary shaft VRo which is coaxially connected to the feed speed varying knob 171 for the speed varying means 17. The feed speed can be set at any level as desired by turning the knob 171 while watching the speed dial 172.

The output of the AC power source AC is rectified by the rectifying circuit REC, passed through the diode D and resistor R7, and smoothed by the capacitor C3 into a DC current which is supplied to the solenoid 20 (23) through the timer 19 (22) which is rendered operative after lapse of a predetermined time interval which can be set as desired to energize the solenoid 20 (23). The time lapsing before the timer 19 (22) is rendered operative may vary depending on the value of the variable resistor VR which is coupled to the knob 171 for the speed varying means 17.

The variable timers 19 and 22 may be formed into one timer performing the functions of two timers. One example of such timer is shown in FIG. 11 wherein the microswitch 18 and solenoid 20 are connected in series between one end 27 of the DC power source and a fixed terminal 281 of a switch while the microswitch 21 and solenoid 23 are connected in series between the end 27 and another fixed terminal 282 of the switch. A variable timer 30 is connected between a movable contact 283 of the switch 28 and the other end 29 of the DC power source. The switch 28 may. for example. be actuated by the stopper 12 when the latter is operated by the solenoid and moves upwardly, so that the movable contact 283 is brought into engagement with the fixed terminal 282. Thus the solenoids 20 and 23 act in the same manner as described with reference to the circuit diagram shown in FIG. 7.

What is claimed is:

l. A copy strip feed error correcting device for copying apparatus of the type wherein an original and a strip of photosensitive material are cooperatingly fed through the apparatus comprising:

a. a speed varying means for setting a common feed speed for said original and said strip of photosensitive material;

b. first drive means for advancing said strip of photosensitive material at a feed speed in accordance with the setting of said speed varying means;

c. second drive means for advancing said original at a feed speed in accordance with the setting of said speed varying means;

d. first detector means for sensing the arrival of a leading end of said strip of photosensitive material and producing a signal in response thereto;

e. second detector means for sensing the arrival of the trailing end of said original and producing a signal in response thereto;

f. cutting means for severing said strip of photosensitive material; and

g. timer means operatively connected to said speed varying means, said second drive means, said first and second detector means and said cutting means for respectively actuating said second drive means and said cutting means in response to said signals from said first and second detector means after a time lapse which is in inverse proportion to the feed speed set by said speed varying means, whereby a sheet of photosensitive material is cut to a length consistent with the length of the original when the feed speed setting is varied by said speed varying means.

2. A device as in claim I wherein said timer means comprises:

h. a rotary shaft coupled to said speed varying means and rotatable in response to the setting of a feed speed thereon;

. a variable resistor whose resistence is varied in response to the rotation of said rotary shaft;

a capacitor connected to said variable resistor and forming a time constant circuit therewith;

k. a programmable unijunction transistor connected to and operable in response to the operation of said time constant circuit; and

l. a thyristor connected to and operable in response to the operation of said programmable unijunction transistor.

7 iv pdvMtv t 

1. A copy strip feed error correcting device for copying apparatus of the type wherein an original and a strip of photosensitive material are cooperatingly fed throUgh the apparatus comprising: a. a speed varying means for setting a common feed speed for said original and said strip of photosensitive material; b. first drive means for advancing said strip of photosensitive material at a feed speed in accordance with the setting of said speed varying means; c. second drive means for advancing said original at a feed speed in accordance with the setting of said speed varying means; d. first detector means for sensing the arrival of a leading end of said strip of photosensitive material and producing a signal in response thereto; e. second detector means for sensing the arrival of the trailing end of said original and producing a signal in response thereto; f. cutting means for severing said strip of photosensitive material; and g. timer means operatively connected to said speed varying means, said second drive means, said first and second detector means and said cutting means for respectively actuating said second drive means and said cutting means in response to said signals from said first and second detector means after a time lapse which is in inverse proportion to the feed speed set by said speed varying means, whereby a sheet of photosensitive material is cut to a length consistent with the length of the original when the feed speed setting is varied by said speed varying means.
 2. A device as in claim 1 wherein said timer means comprises: h. a rotary shaft coupled to said speed varying means and rotatable in response to the setting of a feed speed thereon; i. a variable resistor whose resistence is varied in response to the rotation of said rotary shaft; j. a capacitor connected to said variable resistor and forming a time constant circuit therewith; k. a programmable unijunction transistor connected to and operable in response to the operation of said time constant circuit; and l. a thyristor connected to and operable in response to the operation of said programmable unijunction transistor. 